VSS Does not offer cheap branching, so we hesitate to create branches. Also does not support ActionScript type filenames which forced us to use Subversion for FLEX development. Now we straddle using two Version Control systems.Vault combines the best of VSS and Subversion and adds some enhancements of its own.Surveyed about 20 Version Control systems. Several are cheaper(free), Several are more powerful (AccuRev, Team Concert). Vault has by far the lowest learning curve, has the essential features and is priced competitively.